One Dimensional MotionOne Dimensional MotionSpeed and VelocitySpeed and Velocity

Learning ObjectivesLearning Objectives

TLW know concepts of force and motion evident in TLW know concepts of force and motion evident in everyday life (TEKS 4)everyday life (TEKS 4)

TLW describe and calculate an object’s motion in terms TLW describe and calculate an object’s motion in terms of position, displacement, speed and acceleration (TEKS of position, displacement, speed and acceleration (TEKS 4.A)4.A)

TLW measure and graph distance and speed as a TLW measure and graph distance and speed as a function of time using toys (TEKS 4.B)function of time using toys (TEKS 4.B)

TLW investigate how an object’s motion change only TLW investigate how an object’s motion change only when a net force is applied using toy cars, vehicle when a net force is applied using toy cars, vehicle restraints, sports activities and classroom objects (TEKS restraints, sports activities and classroom objects (TEKS 4.C)4.C)

Anticipatory ActivityAnticipatory Activity

Audience Participation – Audience Participation – Get Your Move Get Your Move On… Grooving to the OldiesOn… Grooving to the Oldies

I. What is MotionI. What is Motion

A. Motion – A. Motion – an object has movedan object has moved

1. change in 1. change in positionposition of an object of an object

2. compared to the 2. compared to the backgroundbackground that is not movingthat is not moving

3. 3. frame of referenceframe of reference – – background used for background used for comparing motioncomparing motion

4. most common frame of 4. most common frame of reference – the reference – the EarthEarth

5. Everything in the universe 5. Everything in the universe movesmoves

B. Motion can be B. Motion can be measuredmeasured1. 1. SpeedSpeed is the easiest way to is the easiest way to measure motionmeasure motion

a. a. position – location of object inreference to an origin

b. displacement – b. displacement – change in position

c. distance – . distance – how far an objecthow far an objectmoves in totalmoves in total

d. time – time – how long it takes an how long it takes an object to moveobject to move

e. speed – speed – how fast an object how fast an object movesmoves

2. Formula for measuring 2. Formula for measuring motionmotion::Speed = distance Speed = distance ÷ ÷ timetime

orors = d / ts = d / t

a. this is used to calculate a. this is used to calculate averageaverage speedspeedb. Ex. A racecar finishes a 500 b. Ex. A racecar finishes a 500 mile race in 3.5 hours. What is the mile race in 3.5 hours. What is the average speed? average speed? s = d / ts = d / t

s = 500 mi / 3.5 s = 500 mi / 3.5 hrhr

s = 142.86 mi / hrs = 142.86 mi / hr

c. Finding distance: c. Finding distance:

Drive 100 mi / hr for 3 hoursDrive 100 mi / hr for 3 hours

how far?how far?

d = vtd = vt

d = 100mi / hr * 3hrd = 100mi / hr * 3hr

d = 300 mid = 300 mi

d. Finding time:d. Finding time:

If you are traveling at 60 mph, how If you are traveling at 60 mph, how long will it take you to get to Austin long will it take you to get to Austin

(120 miles away)?(120 miles away)?

how long?how long?

t = d / vt = d / v

t = 120 miles / 60 miles per t = 120 miles / 60 miles per hrhr

t = 2 hourst = 2 hours

3. 3. UnitsUnits of measure of measure

a. distance = a. distance = meters or kilometersmeters or kilometers

b. time = b. time = seconds or hoursseconds or hours

c. speed = c. speed = meters per secondmeters per second (m/s) or (m/s) or miles per hourmiles per hour (mi/hr) (mi/hr)

C. VelocityC. Velocity

1. motion also includes 1. motion also includes directiondirection

2. 2. VelocityVelocity is the is the speedspeed AND AND directiondirection of an object’s of an object’s motionmotion

3. Velocity is also measured as 3. Velocity is also measured as negativenegative or or positivepositive

a. object moving in a. object moving in oneone direction direction has a has a positivepositive velocity velocity

b. an object moving in the b. an object moving in the oppositeopposite direction has a direction has a negativenegative velocity velocity

c. Ex. A rocket traveling up c. Ex. A rocket traveling up has has a a positivepositive velocity velocity

and as it falls back down it and as it falls back down it has a has a negativenegative velocity velocity

Negative does NOT mean slowerNegative does NOT mean slower

4. Velocity of an object 4. Velocity of an object changeschanges if if an object changes an object changes speedspeed or or

directiondirection

***a car driving in a straight ***a car driving in a straight line at a constant speed does not line at a constant speed does not have a change in velocity***have a change in velocity***

5. Use this formula for 5. Use this formula for velocityvelocityv = d / tv = d / t

BUT you must add BUT you must add directiondirection = = up, down, east, west, etc.up, down, east, west, etc.

Ex. A bird flies 200 meters to Ex. A bird flies 200 meters to the west in 100 seconds, the west in 100 seconds, what is the velocity?what is the velocity?

v = d / tv = d / tv = 200 m / 100 sv = 200 m / 100 sv = 2 m / s to the westv = 2 m / s to the west

The Magic TriangleThe Magic Triangle

d

v t

Group PracticeGroup Practice

Using Graphs to Determine Using Graphs to Determine Displacement and VelocityDisplacement and Velocity

y = mx + b

1.1. How many meters can Swimmer 1 cover How many meters can Swimmer 1 cover in 30 sec?in 30 sec?

2.2. How far will Swimmer 2 go in 30 sec? How far will Swimmer 2 go in 30 sec?

3.3. Predict the number of m Swimmer 1 can Predict the number of m Swimmer 1 can go in 60 secgo in 60 sec

4.4. Predict the number of m Swimmer 2 can Predict the number of m Swimmer 2 can go in 60 sec.go in 60 sec.

5.5. Which swimmer has the greatest speed?Which swimmer has the greatest speed?

6.6. Calculate the speed of Swimmer 1Calculate the speed of Swimmer 1

7.7. Calculate the speed of Swimmer 2Calculate the speed of Swimmer 2

http://www.sidebysidetutoring.com/blogs/wp-content/uploads/2010/09/x-vs-t.jpg

Interpreting the GraphInterpreting the Graph

How far did you travel in the first 2 seconds?How far did you travel in the first 2 seconds?

from 4 m to 6 m -- or 2 mfrom 4 m to 6 m -- or 2 mWhat was your direction?What was your direction?

up or forward or __________up or forward or __________Calculate your speed & velocityCalculate your speed & velocity

v = v = distance traveleddistance traveled 2 m2 m = 1 m/s forward = 1 m/s forward

timetime 2 s 2 s

D. CalculationsD. CalculationsEx. 1 Ex. 1 What is the average speed of a bicycle What is the average speed of a bicycle

that traveled 15 m in 30 seconds?that traveled 15 m in 30 seconds?Know: Know:

d = 15 md = 15 mt = 30 sect = 30 secs = ?s = ?

s = d / ts = d / t

s = d / t

s = 15 m / 30 s

s = .5 m / s

Ex. 2 Ex. 2

A hot air balloon was traveling an A hot air balloon was traveling an average of 2 mi / hr. It traveled for 32 average of 2 mi / hr. It traveled for 32 hours. How far did it travel?hours. How far did it travel?

Know: Know:

v = 2 mi / hrv = 2 mi / hr

t = 32 hourst = 32 hours

d = ?d = ?

v = d / tv = d / t

Use “magic triangle”

d

v t

d = vt

2 mi / h * 32 hrs

d = 64 mi

Ex. 3Ex. 3

A snail crawling 0.005 m / s, traveled a A snail crawling 0.005 m / s, traveled a record breaking 1m. How long did it record breaking 1m. How long did it take the snail to break the record?take the snail to break the record?

Know:Know:

v = 0.006 m / sv = 0.006 m / s

d = 1 md = 1 m

t = ?t = ?

v = d / tv = d / t

use “magic” triangle

v t

dt = d / v

t = 1m / 0.006m/s

t = 200 s

Ex. 4 Ex. 4 How much time do you have to escape How much time do you have to escape

from an elephant charging straight from an elephant charging straight towards you 15 meters away and towards you 15 meters away and running 3 meters per second?running 3 meters per second?

Know:Know:d = 15 md = 15 mv = 3 m / s straightv = 3 m / s straightt =?t =?

v = d / tv = d / t

t = d / v

t = 15 m/ 3 m / s

t = 5 sec

Ex. 5 Ex. 5

What is the velocity of a boat traveling What is the velocity of a boat traveling north 23 meters in 15 seconds?north 23 meters in 15 seconds?

know:know:

d = 23 md = 23 m

t = 15 st = 15 s

v = ?v = ?

v = d / tv = d / t

v = d / t

v = 23 m / 15 s

v = 1.5 m / s north

Independent PracticeIndependent Practice

Motion Calculations – Practice Set 1Motion Calculations – Practice Set 1

LabsLabs One or more of the following labs will be performed from IPC Manual or One or more of the following labs will be performed from IPC Manual or

other sourceother source Physics 500 (Teaching Physics for 1Physics 500 (Teaching Physics for 1stst Time p. 59) Time p. 59) Graphing Student Motion I (Teaching Physics for 1Graphing Student Motion I (Teaching Physics for 1stst Time p. 61) Time p. 61) Hot Wheelin’ (Hot Wheelin’ (link)) What is speed and how is it measured? (IPC Manual - p. 8 & 9)What is speed and how is it measured? (IPC Manual - p. 8 & 9) Can you predict the speed of the car at any point on the ramp? (IPC Can you predict the speed of the car at any point on the ramp? (IPC

Manual - p. 10 & 11)Manual - p. 10 & 11) How do you model motion of the car? (IPC Manual - p. 12 & 13)How do you model motion of the car? (IPC Manual - p. 12 & 13)

Periodic Groups willPeriodic Groups will Read lab procedures togetherRead lab procedures together Set up labs according to scientific methodSet up labs according to scientific method Identify potential hazards, precautions, and PPE (if needed)Identify potential hazards, precautions, and PPE (if needed)